Method of adhesion of surfaces especially as applied to corrugated paper boards

ABSTRACT

A method by which two corrugated paper surfaces are secured together by adhesion during the setting of a permanent glue comprising the freezing of a layer of water introduced between the paper surfaces after a layer of glue has been applied. The time calculated for the water to remain frozen is to be longer than the time required for an inexpensive glue to solidify.

United States Patent Hanley 1 1 Nov. 25, 1975 METHOD OF ADHESION 0F SURFACES 1,951.474 3/1934 Eastman l, 156/80 ESPECIALLY AS APPLIED TO 2,151,653 3/1939 Fincke 53/388 I 2,266,054 12/1941 Lowey et 11].. 53/387 CORRUGATED PAPER BOARDS 2,819,594 1/1958 Lorie 206/427 [76] Inventor: James A. Hanley, 377 Virginia Ave., 3,015,198 2/1962 Becker 53/387 J r y Ci Ni 07304 3,020,691 2/1962 Oxborrow 53/388 3,145,518 8/1964 Ricca 53/387 [22] F11ed: Apr. 29, 1974 3,236,026 2/1966 Evans 53/387 3,329,116 7/1967 Attwood et a1 156/80 [211 Appl' 464338 3,411,267 11/1968 Garrett 53/388 Related 5. A li ti m 3,767,495 10/1973 Miller 156/80 [63] Continuation-impart of Ser. No. 337,946, March 5,

1973, abandoned Primary Exam1ner-D0uglas J. Drummond Assistant Examiner-F. Frisenda 52] US. Cl. 53/47; 53/374; 53/388; Koenig 93/36 M; 156/80 51] int. (:1. B31B 1/26 1571 ABSTRACT [58] Field of Search 156/80, 282, 498, 69, 155, A method by which two corrugated paper surfaces are 156/311; 62/62, 63; 53/47, 374, 375, 387, 53/388; 264/28, 93/36 M, 39 R, 40, 41, 49 M [56] References Cited UNITED STATES PATENTS 1,543,843 6/1925 Gwinn 53/388 1,716,094 6/1929 Tucker 264/28 ILL/III r111 secured together by adhesion during the setting of a permanent glue comprising the freezing of a layer of water introduced between the paper surfaces after a layer of'glue has been applied. The time calculated for the water to remain frozen is to be longer than the time required for an inexpensive glue to solidify.

2 Claims, 7 Drawing Figures US. Patent Nov. 25, 1975 Sheet1of2 3,921,368

US. Patent Nov. 25, 1975 Sheet 2 of2 3,921,368

METHOD OF ADHESION OF SURFACES ESPECIALLY AS APPLIED TO CORRUGATED PAPER BOARDS CROSS-REFERENC E TO RELATED APPLICATION This application is a continuation-in-part of my earlier filed pending application, Ser. No. 337,946, filed Mar. 5, 1973 now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a method and device to secure two or more surfaces such as the flaps of a corrugated paper case, by means of introducing a layer of water already at freezing temperature between the flaps of the case to which glue has been applied and immediately afterwards directing a blast of refrigerated air towards the water to immediately freeze the water to ice. Since the surfaces of the flaps are wetted, the ice thus formed holds the flaps together while the glue dries. The method of the invention can be used for the temporary adhesion of materials such as leather, plastics, or cloth that must be held together while a permanent glue sets.

2. Description of the Prior Art In a conventional case sealer, two methods have been commonly used to secure the surfaces to be adhered to provide time for the glue to solidify: I

1. Use of a long compression belt, whose length is determined by the speed of the output of the production line, to gain the time required for a glue to dry.

2. Use of a fast drying or a fast solidifying glue, namely some type of hot melt glue, combined with a short compression time.

In the first method, a relatively inexpensive glue, such as a dextrin glue with a corn starch base, is normally used. The solidification time for this type of glue is long, thus the surfaces required to be bonded must be held securely fora long time and a compression unit is needed to hold the surfaces together while the glue is hardening. Use of a faster drying glue without raising the temperature involves the use of an expensive glue called cold glue." In the second method, the use of a hot melt glue involves the use of an even more expensive glue than the types used in the first method. In both methods, a case sealing machine manufacturer is obliged to use a compression belt to keep the flaps of a case in a compressed position until the glue used is completely solidified.

Methods of temporarily adhering two materials by chilling the materials themselves or by moistening the materials and freezing are known, but my method has substantial differences from the methods described in the prior art. In particular, my method differs from the method described in US. Pat. No. 3,767,495 entitled "Method of Producing a Non-Woven Pile Product, in which the materials must be stacked and moistened completely, then moved into a freezing chamber. Thereafter the frozen slabs are sliced and must be defrozen and dried before being bonded to a layer of backing material. As an alternate method, the patent teaches the use of water soluble adhesives on the still frozen slab. In addition to having an entirely different purpose from the teachings of the patent, my method differs from those of the patent in that a permanent glue is applied first and is entirely separated from the 2 water used for freezing, thereby completely eliminating the problem of the compatibility of the glue and water. Further, my method requires only a thin layer of water to be applied to the edges of the surfaces to be adhered and provides for freezing the water immediately by the use of a stream of cold air.

SUMMARY OF THE INVENTION It is a principal objective of this invention to extend the time needed for solidifying a glue and to eliminate the need for a compression unit in a corrugated case sealing process.

Another objective of this invention is to enhance the use of inexpensive but slow-setting glues in the corrugated case sealing process.

It is a further object of this invention to provide a method to extend the time needed for solidifying of a glue and to eliminate the need for a compression unit in processes that require two surfaces to be held together while the glue or adhesive hardens.

It is a further object of this invention to provide a method of forming a bead of ice between two surfaces to be bonded by the use of inexpensive equipment BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a conventional case sealer incorporating the apparatus of my invention.

FIG. 2 is a perspective view of a packing case with two flaps in a closed position.

FIG. 3 is a perspective view of a packing case with two side flaps extended outwardly.

FIG. 4 is a perspective view of a packing case with the side flaps folded inwardly.

FIG. 5 is a perspective view of the two manifolds.

FIG. 6 is a partial sectional view of an end view of a packing case with one manifold in operating position.

FIG.,7 is a top plan view of one of the manifolds.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now specifically to the drawings, a conventional case sealer apparatus 11 is shown in FIG. 1. The arrow in FIG. 1 indicates the direction of travel of a case 12 along the case sealer conveyor 13. A conventional corrugated shipping case has four flaps on the top and four flaps on the bottom. As shown in the figures only the top four flaps, indicated by the letters a, b, c, d, are shown. As shown in FIG. I, flap a is attached to the back of the case, flap c to the front of the case and flap b and flap d are attached to the sides of the case 12. Each flap has two surfaces, an inner surface which faces into the case when the case is closed and an outer surface which faces outward of the case when the case is closed. As a case 12 is conveyed along the conveyor 13 in the direction of the arrow shown in FIG. 1, flap c is folded inwardly to a horizontal position over the case by a plow 2 and flap a is folded inwardly to a horizontal position over the case by the sweeping action of an air operated kicker l. The side flaps b, d are then opened to a horizontal position outward from the case by flap guides 3, 4. The flaps b, d of the case 12 are then in a position shown in FIG. 3. Glue applicators (not shown in the drawings) apply glue 14 to portions of the inner faces 15, 16 of the outwardly held side flaps b, d leaving a void 23 between the glue layers 14 so that no glue seeps into the contents of the case through the seam 22 left between the front and back flaps a, when they were closed. The glue is applied to the center portion of each side flap b, d leaving a strip or margin J along the unattached edge of each flap without glue so that a person opening the carton can grasp an unglued portion of the flap to facilitate his opening the case. After the glue is applied, arms 5, 6 hold the flaps b, d above a one hundred eighty degree plane; then foldover flap guides 3a. 4a fold the open flaps through a one hundred eighty degree angle from an outward horizontal position inwardly to a substantially horizontal position over the previously closed flaps a, c, the unglued margins J. J of the side flaps b. 11. being slightly raised from the outer faces of the closed flaps a, c. The case is then in a position shown in FIG. 4. The operation of a conventional case sealer as here described is well known in the art and further details of its operation are not believed to be necessary.

The apparatus of the invention consists of two manifolds, one for water passage 9 and one for air passage 7, each independent of the other. but attached to the same support 17 at the position on the case sealer apparatus 11 where the flap guides 30, 4a fold over the glued flaps b, d of the case. The water manifold 9 is constructed with connecting means 19 such as a pipe, to a refrigerated water supply. The air manifold 7 is constructed with connecting means 20, such as a pipe. to a source of compressed air cooled to a temperature below the freezing temperature of water.

Each manifold is provided with a pair of discharge nozzles 8 diagonally opposite each other and spaced to fit within the junction formed between the unglued strips J J along the unattached edges of the inner faces -l5, 16 of the side flaps b, d and the upper faces 25, 26

of the front and back flaps a. c, as shown in FIG. 6.

In operation the discharge nozzles 8 of the manifolds are covered by the unglued strips J, J of flaps b and d. commencing at the leading or front edge of the case when the flap guides 3a, 4a fold flaps b and d over flaps a and c. At a predetermined signal, refrigerated water is squirted from the water manifold 9 to deposit a layer of water 21 along the line of juncture of the front and back flaps a, c and the slightly raised side flaps b. d, as shown in FIG. 6. As previously described in respect to the application of the glue, the operation of the water manifold can be interrupted at the middle of the case to prevent water from seeping into the contents of the case through the seam 22 formed between the front and back flaps a, 0. Immediately thereafter, a stream of cold air is directed at the layer of water, forming a strip or bead of ice 24 thereby freezing the outer flaps b, d to almost instantly upon contact with the cold air. In practice, the air is cooled to a predetermined temperature below the freezing temperature of water, the exact temperature depending on'the ambient conditions of the sealing operation. The flaps of the carton are held together by the ice for a period long enough for the permanent glue to set. It has been found that the slowest setting glue used in case sealing operations hardens in approximately two' minutes. The ice bead 24 formed between the flaps remains solid without further refrigeration for more than 2 minutes, thus the flaps are firmly held together without compression while the glue sets. After several minutes the ice melts and the water evaporates at room temperature leaving the flaps of the case sealed with the permanent glue.

It can be seen that the method described can be used to temporarily bond any surfaces which are to be permanently secured or bonded by a glue or adhesive and that the method can be adapted for use with other sealing machines. In general, a' glue is applied to at least one of the two surfaces to be bonded and the second surface to be bonded is placed over the glued surface. A thin layer of water is injected or squirted between the edges of the surfaces to be secured and the layer of water is frozen by directing a stream of cold air at the layer of water or by other refrigeration means. The two surfaces are thereby held securely by the ice bead while the glue or adhesive sets. It will thus be seen that I have provided a new and improved method for securing two surfaces together while a permanent glue sets.

I claim:

l. A method of securing the flaps of a conventional shipping case having a front flap, a back flap, and two side flaps each flap having an inner surface which faces into the case when the case is closed and an outer surface which faces outward of the case when the case is closed, comprising:

a. Folding the front and back flaps inward over the case;

b. Applying a layerof glue to the center area of the inner face of each side flap leaving an unglued strip along the unattached edge of each side flap;

c. Folding the side flaps inward over the' front and back flaps over the case;

d. Squirting a thin layer of cold water between the edges of the flaps along the junction of the unglued strips of the side flaps with the upper faces of the front and back flaps;

e. Freezing the layer of water to ice; and

f. Removing the ice by melting the ice and evaporating the water at room temperature.

2. A method of securing the flaps of a conventional shipping case as set out in claim 1 wherein the layer of water is frozen by directing at the layer of water a stream 'of air cooled to a predetermined temperature below the freezing temperature of water. 

1. A METHOD OF SECURING THE FLAPS OF A CONVENTIONAL SHIPPING CASE HAVING A FRONT FLAP, A BACK FLAP, AND TWO SIDE FLAPS EACH FLAP HAVING AN INNER SURFACE WHICH FACES INTO THE CASE WHEN THE CASE IS CLOSED AND AN OUTER SURFACE WHICH FACES OUTWARD OF THE CASE WHEN THE CASE IS CLOSED, COMPRISING: A. FOLDING THE FRONT AND BACK FLAPS INWARD OVER THE CASE; B. APPLYING A LAYER OF GLUE TO THE CENTER AREA OF THE INNER FACE OF EACH SIDE FLAP LEAVING AN UNGLUED STRIP ALONG THE UNATTACHED EDGE OF EACH SIDE FLAP, C. FOLDING THE SIDE FLAPS INWARD OVER THE FRONT AND BACK FLAPS OVER THE CASE; D. SQUIRTING A THIN LAYER OF COLD WATER BETWEEN THE EDGES OF THE FLAPS ALONG THE JUNCTION OF THE UNGLUED STRIPS OF THE SIDE FLAPS WITH THE UPPER FACES OF THE FRONT AND BACK FLAPS; E. FREEZING THE LAYER OF WATER TO ICE; AND F. REMOVING THE ICE BY MELTING THE ICE AND EVAPORATING THE WATER AT ROOM TEMPERATURE.
 2. A method of securing the flaps of a conventional shipping case as set out in claim 1 wherein the layer of water is frozen by directing at the layer of water a stream of air cooled to a predetermined temperature below the freezing temperature of water. 